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Troubleshooting
Guide
Start Up Conditions
THERMAL
EXPANSION
Water supply
systems
may, because
of high line pressure,
fre-
quent
cut-offs,
the effects of water
hammer
and others,
have
installed
devices such as pressure
reducing
valves, check valves,
back flow preventers,
etc. to control
these types of problems.
When
these devices are not equipped
with an internal
by-pass,
and no other measures are taken, the devices cause the water sys-
tem to be closed. As water is heated,
it expands (thermal
expan-
sion) and closed systems do not allow for the expansion
of heat-
ed water.
The water within
the water heater
tank expands
as it is heated
and increases
the pressure
of the water system.
If the relieving
point
of the water heater's
temperature-pressure
relief valve is
reached, the valve will relieve the excess pressure. The tempera-
ture-pressure
relief valve is not
intended
for the constant
relief of thermal
expansion.
This is an unacceptable
condition
and must be corrected.
It is recommended
that any devices installed which could create
a closed system have a by-pass and/or the system have an expan-
sion tank to relieve the pr_sure
built by thermal
expansion
in
the water system.
Expansion
tanks
are available for ordering
through
the Sears Service Center.
Contact
the local plumbing
inspector,
water supplier,
and/or
the Sears Service Center
for
assistance in controlling
these situations.
HOT
COLD
WATER HEATER
COLD WATER
INLET FITTING
HOT
WATERHEATER
(3)
COLDWATER
PRESSURE
INLETFITTING
REDUCING
VALVEWITH
By.PASS
(0
1
EXPANSION
TANK
(z)
PRESSURE GAUGE
WATER
SHUTOFF
RECOMMENDED INSTALLATION
(VERTICAL MOUNTING)
FLOOR, CEILING
JOiSt, ETC.
STRAPPING
Thermal
Expansion Tank Specifications
Model
Tank Capacity
Dimensions
in Inches .! Pipe Fitting
Number
In Gallons
Dia_meter 1 Length
]
On Tank
153.331050
5
11 inches _14_ inches/
_" Male
(0
EXPANSION
(3)
PRESSURE
REDUCING
VALVE WITH
BY-PASS
INLET COLE
WATER
SHUTOFF
1
Expansion Tank Sizing Chart
Ex
-
I Inlet*
]
Water Heater Capacity
[
pans on
Tank
Water
[
(Gallons)
I
Capacity
I Pressure
_73
__ 82
[_ 100
I
Needed
/4_psi
5
I
5
_
5
I
5
I
*Highest
recorded
inlet water pressure
in a 24 hour period
or
regulated water pressure.
NOTE:
Expansion
tanks
are pre-charged
with
a 40 psi air
charge.
If the inlet water pressure
is higher
than 40 psi, the
expansion
tank's
air pressure
must
be adjusted to match
that
pressure, but must not be higher than 80 psi.
(_)
PRESSURE G AUGE
ALTERNATE RECOMMENDED
INSTALLATION
(HORIZONTAL MOUNTING)
STRANGE
SOUNDS
Possible noises due to expansion
and contraction
of some metal
parts during periods
of heat-up and cool-down
do not represent
harmful
or dangerous
conditions.
Condensation
causes sizzling and popping
with the burner area
during
heating
and coolin,_ periods
and should
be considered
normal. See
Condensation
section.
23
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